The method of feeding dairy cows is also known as the Total Mixed Ration, commonly called TMR for short. Dairy cows are fed using the TMR method so that each cow can consume the required nutritional level in a day — and with every bite of feed it takes. This total mixed ration follows a precise formula consisting of good quality forage, vitamins, whole grains, minerals, and protein. To evenly mix all the contents of the ration, breeders need a TMR mixer that delivers consistent results without making workers feel exhausted. Before we discuss the TMR mixer further, it is useful to first understand what TMR is and what the benefits of using it for your ruminant animals are.
Contents
- 1 What Is a TMR Mixer?
- 2 Feed Use Efficiency With the TMR Method
- 3 Why Do Cows Need the TMR Method?
- 4 How Does a TMR Mixer Work?
- 5 TMR Mixer Types and Their Applications
- 6 Key Factors to Consider When Buying a TMR Mixer
- 7 TMR Mixer and Silage: How They Work Together
- 8 Why Choose Jummos for Your TMR Mixer?
- 9 Frequently Asked Questions (FAQ)
What Is a TMR Mixer?
A TMR mixer — short for Total Mixed Ration mixer — is a piece of agricultural machinery specifically designed to blend all components of a livestock feed ration into a single, homogeneous mixture. The machine combines forage (such as silage, haylage, or hay), concentrates, grains, protein supplements, vitamins, and minerals into one uniform feed that is ready to be distributed to animals.
The key function of a TMR mixer is not just mixing — it also chops and processes materials of varying particle sizes, moisture content, and bulk density into a consistent texture. This prevents animals from selectively eating preferred components and ignoring others, which is a common problem with conventional separate feeding. TMR mixers are available in several configurations, including stationary vertical auger mixers, trailed horizontal mixers, and self-propelled models, each suited to different farm sizes and operational requirements.
Feed Use Efficiency With the TMR Method
For breeders who have not paid close attention to the nutritional outcomes of their ruminants, the use of TMR was historically seen only as a way to increase livestock weight before the slaughter period or during peak selling seasons such as Eid-Al-Adha or the Christmas and New Year period. However, the TMR method has evolved far beyond this limited application.
If previously farmers provided conventional feed where fibre sources and concentrate feed were given separately, the TMR method has now become part of the daily routine in modern farms — practical, measurable, and effective. The development of the TMR mixer has made it straightforward to feed tens or even hundreds of ruminant animals with consistent nutritional precision. This method has proven useful in the following ways:
- Saving labour costs because the entire feeding process can be managed with one TMR mixer, often requiring only one or two workers.
- Improving feed use efficiency, as the mixed ration can be fed freely to high-producing groups without the risk of overfeeding late-lactating or lower-producing cattle.
- Making it easier for livestock to eat because there is no need for animals to sort through forage rations, seeds, protein supplements, minerals, and vitamins — all of which have been thoroughly mixed.
- Improving cow health and milk production, with reproductive activity also increasing as a result of receiving the right nutrients in the right proportions.
- Allowing greater flexibility in delivering the right amounts of energy, protein, fibre, and micronutrients to any herd group.
Why Do Cows Need the TMR Method?
Cows naturally tend to pick through feed, selecting long particles in search of finer, more palatable components. If this sorting behaviour is left unchecked, it becomes a serious health risk. Cows that selectively consume high-concentrate feed relative to fibre can develop metabolic disorders such as rumen acidosis (SARA — Sub-Acute Ruminal Acidosis). This condition occurs when large amounts of low-fibre, rapidly fermentable carbohydrates are consumed, which can lead to a drop in rumen pH, dehydration, and depression.
In intensively reared cattle, another common disorder is alkalosis — caused by the excessive production of ammonium from protein-rich feed that ferments rapidly in the rumen, resulting in excitation and hyperesthesia. Clinical signs of severe metabolic imbalance in cattle can include sunken eyes, blindness, and diarrhoea within 24 hours, with a sour smell and frothy, yellowish-brown to greyish appearance.
To prevent these outcomes, a balanced TMR diet must be applied consistently. After collecting forage properly, the material should be stored in the form of silage or haylage using a round bale wrapper before being held in storage for several months. When feeding time comes, the silage is opened and processed through a TMR mixer to produce feed with the ideal particle size — not too coarse and not too fine.
How Does a TMR Mixer Work?
Dairy cattle in the era of modern farming are highly dependent on the quality and consistency of the TMR mixer. The mixed ration will be well received by ruminant animals when the TMR mixer processes the feed correctly — chopping and blending all components so the resulting mixture has a uniform particle size and texture throughout.
The TMR mixer works by combining feed materials of different particle sizes, moisture content, and bulk density until a homogeneous mixture is achieved. This is the condition where each material placed into the mixing tank ends up at the same concentration in every portion of the finished ration. When a cow takes a full mouthful, it receives all feed components in their correct proportions. This eliminates selective feeding behaviour, which — as discussed — can be metabolically damaging if left unmanaged.
TMR Mixer Types and Their Applications
Choosing the right TMR mixer configuration depends on the size of your herd, the type of forage used, and your farm’s operational layout. The table below summarises the main types available and their typical applications.
| Type | Drive Method | Best For | Key Advantage |
|---|---|---|---|
| Vertical auger (stationary) | Electric or PTO | Small to medium farms with fixed feeding areas | Lower cost, simple maintenance |
| Vertical auger (trailed) | Tractor PTO | Medium farms with multiple feeding points | Mobility, suitable for silage with long fibres |
| Horizontal auger (trailed) | Tractor PTO | Large farms with high daily feed volumes | High capacity, gentle mixing action |
| Self-propelled | On-board engine | Large commercial dairy operations | No tractor required, maximum efficiency |
Key Factors to Consider When Buying a TMR Mixer
Investing in a TMR mixer is a significant capital decision, and selecting the wrong machine for your operation can result in poor feed quality, unnecessary mechanical stress, or inadequate capacity. The following factors should guide your evaluation:
- Mixing capacity (cubic metres or litres) — The tank volume must match your daily feed requirements. As a general rule, allow approximately 1.5 m³ of mixer capacity per 10 dairy cows fed per batch.
- Forage type compatibility — If your ration includes long-fibre hay or whole crop silage, a vertical auger mixer with cutting knives is essential. Horizontal mixers are better suited to pre-chopped or fine-particle forages.
- Power source — Trailed models require a compatible tractor with sufficient horsepower (typically 90 HP or more). Electric stationary models are suitable where a reliable power supply is available.
- Weighing system — A built-in load cell weighing system allows the operator to add each ingredient precisely according to the ration formula, which is critical for consistent nutritional delivery.
- After-sales support and spare parts — Ensure the supplier can provide replacement parts and technical support in a timely manner, as a breakdown during feeding time has an immediate impact on animal welfare and production.
TMR Mixer and Silage: How They Work Together
The TMR mixer and silage production are closely linked in any modern dairy or beef operation. Silage — whether grass, maize, or legume-based — typically makes up the largest volume component of a TMR ration. The quality of the silage fed into the TMR mixer directly affects the quality of the finished ration and, ultimately, animal performance.
For farms using round bale silage, the workflow typically runs as follows: forage is harvested and baled, bales are wrapped using a round bale wrapper with stretch silage film, bales are stored for a minimum of six weeks to complete the fermentation process, and then opened and loaded into the TMR mixer at feeding time. The TMR mixer then processes the silage together with concentrates, minerals, and any other ration components into a uniform feed ready for distribution.
The quality of the silage wrapping at the baling stage has a direct bearing on what goes into your TMR mixer months later. Poorly wrapped bales that allow oxygen infiltration will produce spoiled or unstable silage, which introduces mycotoxins and spoilage organisms into the TMR ration — with measurable negative effects on cow health and milk production.
Why Choose Jummos for Your TMR Mixer?
Maybe you are wondering where to find a reliable TMR mixer at a competitive price with dependable after-sales support. Jummos — Tsingtao Jummos Agricultural Technology Co., Ltd. — is a China-based agricultural machinery supplier specialising in TMR mixers and round bale wrappers for the global market. Our machines are built for practical farm use, with a focus on durability, ease of operation, and cost performance. Contact our team to discuss your herd size, forage type, and daily feeding requirements, and we will recommend the most suitable TMR mixer configuration for your operation.
Frequently Asked Questions (FAQ)
What does TMR stand for in dairy farming?
TMR stands for Total Mixed Ration. It refers to a feeding system in which all feed ingredients — including forages such as silage or hay, concentrates, grains, protein supplements, vitamins, and minerals — are blended together into a single, uniform mixture before being offered to cattle. The goal is to ensure that every mouthful of feed a cow takes contains all nutrients in the correct proportions, eliminating selective feeding and supporting consistent nutritional intake across the herd.
How many cows can one TMR mixer serve per day?
This depends on the capacity of the mixer and the number of batches mixed per day. A small vertical auger mixer with a 5 m³ tank can typically serve a herd of 50–80 cows per batch, depending on the ration dry matter content and bulk density. Larger horizontal mixers with 20–30 m³ capacity can serve herds of several hundred cows. Most farm operations run one to two mixing batches per day, though larger operations may run three or more. Always size the mixer to your peak daily feed volume rather than average volume to avoid bottlenecks.
What is rumen acidosis and how does TMR prevent it?
Rumen acidosis is a metabolic disorder in cattle caused by rapid fermentation of large amounts of low-fibre, high-carbohydrate feed in the rumen, resulting in a sudden drop in rumen pH. Sub-acute rumen acidosis (SARA) is the more common subclinical form, which reduces feed intake, milk production, and reproductive performance without producing obvious visible symptoms. The TMR system prevents rumen acidosis by ensuring that fibre, concentrate, and other components are physically blended together, so the cow cannot sort and overconsume concentrates relative to fibre. Each mouthful contains both forage and concentrate in the correct ratio, which supports a stable rumen environment and healthy pH.
Can a TMR mixer handle whole bale silage directly?
Most vertical auger TMR mixers are capable of accepting and processing round bale silage directly into the mixing tank without pre-cutting, provided the machine is equipped with cutting knives on the auger. The rotating auger pulls the silage from the bale and progressively chops it to the desired particle length while mixing it with other ingredients. Horizontal mixers typically require the silage to be pre-shredded or loaded in smaller sections. Always check the manufacturer’s specifications for maximum bale dimensions and recommended loading procedures before placing a whole bale into the mixer.
What is the ideal particle length for TMR feed?
The Penn State Particle Separator is the standard tool used on farm to evaluate TMR particle size distribution. For a high-producing dairy cow ration, the general targets are: less than 10% of particles on the top screen (particles longer than 19 mm), 30–50% on the second screen (8–19 mm), 10–20% on the third screen (1.18–8 mm), and less than 20% in the pan (under 1.18 mm). A ration that is too fine increases the risk of rumen acidosis, while a ration that is too coarse encourages sorting behaviour. Regular particle size checks using a shaker box are a simple and practical quality control measure for any TMR operation.
Last reviewed by the Jummos Technical Team – 7 April 2026